The AC/heater (HVAC) system may unexpectedly switch to the defrost mode when accelerating. This system is operated by engine vacuum and should be inspected for any vacuum leaks if this problem develops. There is also a revised vacuum check valve available to address this concern.

Some vehicles may exhibit one or more of the following: Spark knock complaints when the vehicle is under load, various single cylinder misfire, and surge in 4th gear (around 45 mph). Our technicians tell us that rerouting the coil and spark plug wires to minimize induction effects will commonly correct this condition. If wires must cross during the reroute procedure, they must cross at a 90 degree angle.

2003 dodge w/ 5.9 cummins. oil leaks from crankcase breather where it goes into valve cover. It has new breather and o ring. Has 385000 miles very well maintained. No problems with performance runs good no lack of power.No pressure when oil filler cap taken off to indicate broken ring etc.Any inf...